Hello Spin Class Folks:
Those of you who know about spin bikes please answer me this: What brand or model of spin bike has the largest flywheel? I’m looking for the flywheel with the highest moment of inertia but as a first pass I’d like to know what spin bikes have either larger diameter flywheels or more massive or both. My Google searches have not turned up the kind of thing I am looking for so if you have inside info please let me know.
Thanks in advance,
Jim
i think the lemond one, as the fan is a big iron hunk.
Kurt Kinetic makes a “Pro flywheel” which is 15 pounds.
http://www.amazon.com/Kinetic-by-Kurt-Pro-Flywheel/dp/B0058TG8WW
“For use with Kurt Kinetic Fluid Bike Trainers manuafactured after January 1, 2010. (serial #'s 76184 and higher)”
Thanks guys. Those are both good trainers but I am looking for spin bikes. As in JohnnyG and similar.
Yeah, it looks like it’s about 50#
.
Thanks guys. Those are both good trainers but I am looking for spin bikes. As in JohnnyG and similar.
I know of a few around 50 lbs. Are you looking for bigger than that? Is there a reason?
-Physiojoe
I know of a few around 50 lbs. Are you looking for bigger than that? Is there a reason?
Can you point me toward one of those please?
Yes there is a reason. In my lab we use a maximum power test (as in all sprint for a few seconds) called the inertia load test. In the past we have always used standard Monark ergometer flywheels which will give the appropriate inertial load (at the cranks) when used with pretty big gear ratios. Some of my colleagues are interested in setting up this test in their lab and I’m wondering if I could purchase a standard spin bike and covert it to inertia load use. The Monark flywheels are about 20kg with a moment of inertia of about 0.9 kgm2. If I could find something a bit bigger than that I might be able to set things up with relatively normal gear ratios. Below is the abstract for the original methods paper.
Med Sci Sports Exerc. 1997 Nov;29(11):1505-12.
Inertial-load method determines maximal cycling power in a single exercise bout.
Martin JC, Wagner BM, Coyle EF.
Source
Department of Kinesiology and Health Education, University of Texas at Austin 78712, USA.
Abstract
A cycle ergometer was modified to measure power (P) with resistance provided solely by the moment of inertia (I) of the flywheel. P was calculated as the product of I, angular velocity (omega), and angular acceleration (alpha). Flywheel omega and alpha were determined by means of an optical sensor and a micro-controller based computer interface which measured time (+/- 1 microsecond) and allowed P to be calculated instantaneously (PI) every 3 degrees of pedal crank rotation or averaged over one complete revolution of the pedal cranks (PREV). Values for maximum P were identified from each bout (PI max and PREV max). Mechanical calibration of torque via a resistive strap proved this method to be both valid and accurate. Thirteen active male subjects performed four bouts of maximal acceleration lasting approximately 3-4 s with 2 min resting recovery. The mean coefficient of variation for PREV max was 3.3 +/- 0.6% and the intraclass correlation was 0.99. PREV max averaged 1317 +/- 66 W at 122 +/- 2 rpm, and PI max averaged 2137 +/- 101 W at 131 +/- 2 rpm. PREV max and PI max were highly correlated (r = 0.86 and r = 0.80 respectively, P < 0.002) with estimated lean thigh volume. Therefore, the inertial-load method provides a valid and reliable determination of cycling power in one short exercise bout.
The gym I recently joined has the Schwin A.C. Performance bikes that are the best I’ve used.
Very adjustable, very smooth spin, but the best feature is the integral ANT+ Power Meter. You can
synch to a Garmin watch (some, not all) or download the workout to a USB memory stick.
The resistance I think is magnetic, not a felt pad, so the resistance increase is predictable. Not cheap,
but less than a set of wheels. I think someone said we’re working on the engine this year, not the aero.
.
Spin bikes or spin trainers?
If trainers then Kurt used to do a ‘pro’ version. But now they just sell the standard versions with an aftermarket flywheel add on which costs around $70
Flywheel Image Pdf … pro flywheel on Amazon
Not sure if it is the biggest but it should be up there.
The current Vision Fitness spin bike (ST2010) has a flywheel of around 41 ish pounds. It actually dropped a few pounds from the previous model (ES7007) that is closer to 50. Visionfitness.com. Looks like you are in Utah- if you were farther east I could give you a deal 
The ES7007 should be around for $700-$800. If you need me to email you a quote for bargaining sake let me know.
-Physiojoe
I know of a few around 50 lbs. Are you looking for bigger than that? Is there a reason?
Can you point me toward one of those please?
Yes there is a reason. In my lab we use a maximum power test (as in all sprint for a few seconds) called the inertia load test. In the past we have always used standard Monark ergometer flywheels which will give the appropriate inertial load (at the cranks) when used with pretty big gear ratios. Some of my colleagues are interested in setting up this test in their lab and I’m wondering if I could purchase a standard spin bike and covert it to inertia load use. The Monark flywheels are about 20kg with a moment of inertia of about 0.9 kgm2. If I could find something a bit bigger than that I might be able to set things up with relatively normal gear ratios. Below is the abstract for the original methods paper.
Med Sci Sports Exerc. 1997 Nov;29(11):1505-12.
Inertial-load method determines maximal cycling power in a single exercise bout.
Martin JC, Wagner BM, Coyle EF.
Source
Department of Kinesiology and Health Education, University of Texas at Austin 78712, USA.
Abstract
A cycle ergometer was modified to measure power (P) with resistance provided solely by the moment of inertia (I) of the flywheel. P was calculated as the product of I, angular velocity (omega), and angular acceleration (alpha). Flywheel omega and alpha were determined by means of an optical sensor and a micro-controller based computer interface which measured time (+/- 1 microsecond) and allowed P to be calculated instantaneously (PI) every 3 degrees of pedal crank rotation or averaged over one complete revolution of the pedal cranks (PREV). Values for maximum P were identified from each bout (PI max and PREV max). Mechanical calibration of torque via a resistive strap proved this method to be both valid and accurate. Thirteen active male subjects performed four bouts of maximal acceleration lasting approximately 3-4 s with 2 min resting recovery. The mean coefficient of variation for PREV max was 3.3 +/- 0.6% and the intraclass correlation was 0.99. PREV max averaged 1317 +/- 66 W at 122 +/- 2 rpm, and PI max averaged 2137 +/- 101 W at 131 +/- 2 rpm. PREV max and PI max were highly correlated (r = 0.86 and r = 0.80 respectively, P < 0.002) with estimated lean thigh volume. Therefore, the inertial-load method provides a valid and reliable determination of cycling power in one short exercise bout.
The current Vision Fitness spin bike (ST2010) has a flywheel of around 41 ish pounds. It actually dropped a few pounds from the previous model (ES7007) that is closer to 50.
Thanks Physiojoe. I’ll look around a bit more and may get back to you.
I have the Star Trac Spinner NXT. I don’t know if it’s the largest flywheel but it’s very smooth and you can hammer on it. I just put some looks on it and use my bike shoes.
http://www.startracusa.com/…-11-spinner-nxt.aspx
BTW this is the same bike they have at my sports club.
Highest moment of inertia I’ve seen would be a tossup between the Star Trac and older Schwinn bikes.
Definitely not the yellow LeMond, Keiser, or new Livestrong bike.
Highest moment of inertia I’ve seen would be a tossup between the Star Trac and older Schwinn bikes.
Thanks!